1. Field of the Invention
This invention relates to a CT image processor in an X-ray computerized tomograph.
2. Discussion of Prior Art
As disclosed in Japanese Patent Application Laid-Open No. 53-9494, there has been proposed a method for adjusting an object being examined so that the object may be accommodated to a maximum extent within the spread out angle of a fan beam by moving the object-arranging mechanism in an X-ray source-multi-channel detector system to improve image quality when a small object being examined is involved. FIGS. 12(A) and (B) illustrates in outline the method.
The CT processor shown in FIGS. 12(A) and (B) is assumed capable of rearranging the order of fan/parallel beams. In the CT processor, the interpolative operation is carried out from fan to parallel beams at a one-to-one ratio. When an object being examined is smaller, there will be certain channels which are not effectively utilized.
FIG. 12(A) illustrates such a case wherein, because an object being examined is smalled in diameter than the width of the fan beam from an X-ray source 1, blank channels are produced as shown by the slanted lines within the detector 1.
The distance between the X-ray source and object 3 is relatively shifted as shown in FIG. 12(B) to avoid the aforementioned phenomenon. Accordingly, all of the detector channels can be effectively utilized.
Nevertheless, the shifting mechanism is still required and this is disadvantageous.